The present invention relates to a method for making cartons for packaging ordered groups of products and the relative cartoning device.
In particular, the method and device disclosed refer to cartons for packaging ordered rows of filter bags for tea, chamomile, or other products for infusion.
In the sector of automatic packaging machines for products for infusion in filter bags, and in particular those machines with mediumxe2x80x94low productivity, there is not always a cartoning device for preset groups of filter bags attached directly to the packaging machine or connected directly to said machine by feed devices.
Machines with this type of productivity are, for example, but without limiting the scope, those used to make single lobe filter bags, that is to say, bags with a single chamber which holds the product for infusion, with heat-sealing on three edges of the filter bag and folding of the fourth edge, and with a pickup tag and thread to aid infusion attached to the filter bag.
For such machines, cartoning can often be done manually by an operator, or in an independent station of the filter bag machine.
In contrast, the use of cartoning devices is common on high quality and high productivity machines. The devices are located downstream of a final station on the filter bag machine. This final station is designed to prepare a given number of filter bags (normally in rows consisting of a preset number) and transfer them into cartons for collective packaging, formed and suitably positioned by the device.
These devices comprise numerous devices for automatic handling of the cartons in order to perform the following stages in succession and with a high level of productivity: picking up the cartons in the form of flat blanks from a feeder; transferring the cartons to an erecting station equipped with a fixed hopper and a mobile rod which interact for three-dimensional carton erection (which may include gluing); feeding the open cartons to a filling station; closing the cartons by folding the lid and, finally, moving the cartons full of products towards a station at which they are ejected from the cartoning device.
This succession of stages is performed in several stations equipped with conventional (that is to say, mechanical or pneumatic and mechanical) pickup, release, folding and movement devices which allow carton feed during its three-dimensional erection and subsequent feed in steps suitably synchronized with the rest of the machine according to the number of filter bags to be cartoned.
These cartoning devices operate in a satisfactory manner and are highly reliable. However, the particular construction and the type of mechanical technology used for their automatic handling devices makes their construction quite complex and expensive when designed for the type of packaging machines described above, as well as necessitating a large space for installation of the device close to the packaging machine.
For this reason, it became necessary to simplify the method for forming the cartons used for packaging the filter bags and to envisage an extremely compact cartoning device which requires very little space even for the carton handling parts, to allow a reduction in the space required on the packaging machine and to cut the costs of the machine.
Accordingly, the present invention provides a method for packaging one or more rows of filter bags in cartons which comprises a stage of feeding one carton at a time, in the form of a flat pre-folded blank, on a loading table, simultaneously erecting the blank, to form a tubular carton body with two opposite openings, one on either side, two first pairs of smaller flaps and two second pairs of larger flaps or lids. The two pairs of smaller flaps are folded over following insertion of the filter bags in the carton body, as it is fed along in a preset carton direction of feed, to form a first partial closure of the openings. Finally, the carton body is closed by simultaneous folding of the pair of lids towards the two openings to obtain a closed package.